1. Field of the Invention
The present invention relates to a sheet conveying apparatus for conveying sheets and an image forming apparatus including the same.
2. Description of the Related Art
In general, an image forming apparatus includes a sheet conveying apparatus, and a conveying roller is widely used as a sheet conveying portion. In such a conveying roller, in order to drive the conveying roller device while supporting the roller shaft using bearings provided in both side frames of the conveying path, a driving conveyance mechanism such as a driving motor or a gear device is arranged at the near side or the inner side of an apparatus body.
In the image forming apparatus of the related art having such a configuration, members for supporting and driving the sheet conveying apparatus are arranged at both sides of the conveying path. Therefore, the depth of the apparatus significantly increases in comparison with the width of the sheet that can be conveyed through this conveying path. For this reason, the depth of the apparatus may significantly increase in comparison with the width of the conveyed sheet, and a mechanism for transmitting a driving force may become complicated.
In this regard, Japanese Patent Laid-Open No. 07-277545 discloses a sheet conveying apparatus adapted to drive a belt within a conveyance width of the sheet by integrating a conveying roller and a pulley. In this sheet conveying apparatus, both ends of a plurality of shafts where a plurality of feeding rollers is fixed is axially supported, pulleys are integrally provided in each of the intermediate portions of two feeding rollers, and additional pulleys are integrally provided in each intermediate portion of additional feeding rollers.
In addition, a toothed belt is suspended between each pulley of the two feeding rollers, and an additional toothed belt is suspended between the pulleys of the additional feeding rollers. One of the two feeding rollers and one of the additional feeding rollers are coaxially supported by a shaft, and the pulley installed in the rotational shaft of the motor arranged in the chassis meshes with the toothed belt suspended between the two feeding rollers. For this reason, as the motor is driven, a driving force of the motor is transmitted to each feeding roller through the shaft. As a result, the width of the sheet conveying apparatus is approximately equal to the width of the sheet conveying path so as to achieve miniaturization.
In addition, there has been proposed an image forming apparatus in which a gear is installed and driven in an intermediate portion of the roller to reduce the depth of the apparatus (refer to Japanese Patent Laid-Open No. 2000-038237). In such an image forming apparatus, a driving roller member having a roller in the shaft shorter than the width of the sheet is arranged in the conveying path including a feeding system and a receiving system arranged in the image forming apparatus. In addition, a gear is formed in the intermediate portion of the driving roller member so that a driving force is transmitted from one of a series of gears of the drive transmission system through a bevel gear. In addition, a driving force is transmitted in an intermediate portion of the roller by forwardly and reversely rotating the motor arranged in the driving device, where the roller member arranged in the sheet conveying path has a width shorter than the sheet width.
However, in the apparatuses disclosed in Japanese Patent Laid-Open Nos. 07-277545 and 2000-038237, the size of the apparatus body in the depth direction can be reduced. However, the size in the height or width direction increases accordingly. Therefore, it is difficult to implement a compact apparatus in its entire size.
The present invention provides a sheet conveying apparatus capable of implementing miniaturization of the entire size of the apparatus body by preventing projection in the depth, height, and width directions and an image forming apparatus including the same.